Mr. thompson, a retiree, looks at his check register.

date description amount balance

2/16 jimmy's socks $4.50 $647.52

2/17 weekly rent $104.92 $542.60

2/18 groceries $33.45 $509.15

2/20 insurance $359.65 $149.50

2/21 pharmacy $51.35 $98.15

2/21 burger $5.50 $92.65

2/22 deposit $506.28 $598.93

2/23 check $82.12 $516.81

2/24 weekly rent $104.92 $411.89

2/28 movie $15.73 $396.16

3/3 weekly rent $104.92 $291.24

3/5 groceries $28.56 $262.68

3/8 deposit $506.28 $768.96

3/18 car maintenance $173.28 $595.68

what is mr. thompson's yearly rent (using 52 weeks)? $

5455.84

what was the average grocery expense in this time period? $

3224.52

knowing that he buys groceries twice monthly for an average amount,

mr. thompson estimates his yearly expense for groceries to be( 2 · 12 · $

31.01

) or $744.24.

then, mr. thompson realizes